Portion of a shoe sole



FIG. 1 is a front perspective view of a portion of a shoe sole showing my new design;

FIG. 2 is a plan view thereof; and,

FIG. 3 is a rear perspective view thereof.

The broken line showing of the remainder of the shoe is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a portion of a shoe sole, as shown and described. 